Protective enclosure and mount for radioactive elements



June 10, 1969 T. M. SMITH 3,449,575

PROTECTIVE ENCLOSURE AND MOUNT FOR RADIOACTIVE ELEMENTS Filed Sept. 23, 1965 FIG-l FIGZ INVENTOR THEODORE M. SMITH ATTORNEYS United States Patent 3,449,575 PROTECTIVE ENCLOSURE AND MOUNT FOR RADIOACTIVE ELEMENTS Theodore M. Smith, 14750 Puritan Ave., Detroit, Mich. 48227 Filed Sept. 23, 1965, Ser. No. 489,522 Int. Cl. G21h 5/02 US. Cl. 250-106 7 Claims ABSTRACT OF THE DISCLOSURE A protective enclosure and mount which includes removably nested Within an annular groove of a metal support band, a split metallic ring impregnated with radioactive material, the metallic window band mounted over the support band and enclosing said ring, and spaced oppositely arranged annular retainers with outer radial flanges mounted and sealed over said window and support bands.

The present invention relates to a protective enclosure and mount for radioactive elements, and more particularly to elements, rings or parts which have been impregnated with a radio-isotope or other radioactive material.

Elements impregnated with radioactive material or with radioactive-isotopes have many uses in industry, one such use being in apparatus employed for tool failure detection systems and wherein the exposure of a normally shielded radioactive element operates an electronic signal device to indicate a tool failure or other happening or event, which due to a relative movement of parts exposes the radioactive element.

In the use of elements impregnated with radioactive materials, there is the problem of protectively enclosing and mounting such elements as to render them conveniently mountable upon workpieces or other objects.

It is, therefore, the primary object of the present invention to provide a protective enclosure and mount for elements which have been impregnated with radioactive materials for safety factors, for convenience of use and for providing a complete enclosure for the radioactive material and to facilitate reuse of the support and assembled parts after the radioactive material has been exhausted.

This and other objects will be seen from the following specification and claims in conjunction With the appended drawing, in which:

FIG. 1 is a front elevational view of the present protective enclosure and mount for radioactive elements.

FIG. 2 is a section taken in the direction of arrows 2-2 ofFIG. 1.

FIG. 3 is an exploded, perspective view of the present enclosure.

It will be understood that the above drawing illustrates merely a preferred embodiment of the invention, and that other embodiments are contemplated within the scope of the claims hereinafter set forth.

Referring to the drawing, the present protective enclosure and mount for radioactive elements, includes a metallic band 11, which may be constructed of stainless steel, and which is preferably rectangular in cross-section and has upon its exterior a centrally arranged continuous annular groove 13.

A split metallic ring 15 preferably constructed of stainless steel and impregnated with a radioactive material or a radio-isotope and including spaced ends, FIG. 3, is removably nested within groove 13.

A metallic window band 17 preferably of stainless steel and rectangular in cross-section, is mounted over and co-extensive with support band 11 completely enclosing impregnated ring 15. Said window band has overlapped end portions 19, and being constructed of a resilient material is yieldably positioned over and around support band 11 for snugly enclosing impregnated ring 15.

The assembly of support band 11, ring 15 and window band 17 has applied to the exposed surfaces thereof, a suitable adhesive such as an epoxy adhesive in the form of a surface coating 25.

A pair of spaced oppositely arranged annular metallic retainers 21, including outer inwardly directed radial flanges 23 are compressively and snugly mounted and sealed over the window band and over the respective ends of said window band and support band as shown in FIG. 2.

An illustration of the epoxy adhesive employed is a product identified as EC 1386 made and sold by Minnesota Mining and Manufacturing Company.

In the assembly of retainers 21 a clamping pressure of approximately 25 pounds p.s.i. is employed to effectively secure the flanged retainers in the assembled relationship shown.

Thereafter, the assembly is cured in an oven at approximately 375 F. for approximately one hour.

Thus, there is provided a protective enclosure and mount for a radioactive element which is of thin cross section area for occupying a minimum space, and which can be mounted on a tool or other object.

By impregnating or otherwise rendering ring 15 radioactive and nesting the same within groove 13 of support band 11, there is provided a concentration of the radioactive material. Ring 15 is protectively enclosed and retained within said groove by the band-like enclosure or window band 17. The radioactive rays are freely transmittable through stainless steel band 17. This reduces the amount of radioactive material required.

The assembly is furthermore enclosed by the opposed pair of retainers 21 which are fixedly secured in position and sealed in the assembled relation shown using a suitable adhesive, This provides a complete protective enclosure for the radioactive element.

The construction is such that after the active material has been exhausted, ring 15 can be replaced and all of the other parts again used.

In the illustrative embodiment retainers 21 are spaced apart at their opposed edges defining a gap 27 therebetween which is substantially coextensive with the radioisotope impregnated band 15 In the illustrative embodiment ring 15 and window band 17 are resilient to facilitate assembly with respect to support band 11. The active material provides either a beta radiation or a low energy gamma radiation and may be selected from any one of many sources, as for example strontium-90, cerium-144, krypton-85, thallium-204, radium D and radium E, by way of illustration but not by way of limitation, since it is contemplated that other nuclides may be suitable for this purpose.

By wa of explanation, in the illustrative embodiment, split ring 15 has the dimensions .040" x .003" and the window band 17 has the dimensions .25" x .003". The gap between the ends of ring 15 is approximately .10 inch and the overlap 19 on the band ends is approximately .10 inch.

Having described my invention, reference should now be had to the following claims.

I now claim:

1. A protective enclosure and mount for radioactive elements comprising:

an annular metallic support band having an exterior central annular continuous groove;

a split metallic ring impregnated with a radioactive active material and removably nested in said groove;

a metallic Window band mounted over and coextensive with said support band enclosing said ring;

and a pair of spaced, oppositely arranged, annular retainers with outer radial flanges compressively and snugly mounted and sealed over the window band and the ends of said window band and support band.

2. In the protective enclosure of claim 1, the inner opposed annular edges of said retainers defining a gap substantially coextensive with said ring 3. In the protective enclosure of claim 1, said radioactive material selected from a group consisting of strontium 90, cerium 144, krypton 85, thallium 204, radium D and radium E.

4. In the protective enclosure of claim 1 said support band, said ring and said window band being of rectangular cross-section.

5. In the protective enclosure of claim 1, said ring and said window band being of stainless steel.

6. In the protective enclosure of claim 1, said ring being resilient with its ends defining a gap, the window band being resilient with its ends overlapped.

7. In the protective enclosure of claim 1, the sealing of said retainers including a surface coat layer of an epoxy adhesive applied to the assembled exposed surfaces of the support and Window bands.

References Cited UNITED STATES PATENTS 2,025,338 12/1935 Capart 250-106 X 2,479,882 8/1949 Wallhausen et 211. 2,938,125 5/1960 Marak. 2,965,758 12/1960 Malick.

ARCHIE R. BORCHELT, Primary Examiner, 

